Donovan T J, Gallacher S, Andrews N J, Greenwood M H, Graham J, Russell J E, Roberts D, Lee R
Food, Water and Environmental Laboratory, PHLS Central Public Health Laboratory, London.
Commun Dis Public Health. 1998 Sep;1(3):188-96.
The standard method for counting Escherichia coli in live bivalve molluscs is labour intensive and takes three days to obtain a result. Modifications to the standard method were investigated in a collaborative trial conducted in five centres. No significant difference was found between results based on the presence of acid at 24 hours (h) in first stage tests and those based on the presence of acid and gas after 48 h (standard method). The use of the chromogenic medium BCIG (5-bromo-4-chloro-3-indolyl-beta-D glucuronide) agar incubated at 44 degrees C to confirm first stage tests was also found to give equivalent results to conventional confirmation tests. The preferred, modified method removes the presence of gas as a criterion of detection, uses a chromogenic agar medium to confirm the presence of E. coli, and gives results within 48 h. A distribution of simulated samples and selected strains of E. coli to other laboratories using the PHLS external quality assurance scheme for shellfish found no significant difference between results obtained by the standard and modified methods.
在活双壳贝类软体动物中计数大肠杆菌的标准方法劳动强度大，需要三天才能得出结果。在五个中心进行的一项协作试验中，研究了对标准方法的改进。在第一阶段试验中，基于24小时（h）时酸的存在得出的结果与基于48小时（标准方法）时酸和气体的存在得出的结果之间没有显著差异。还发现，使用在44摄氏度下培养的显色培养基BCIG（5-溴-4-氯-3-吲哚基-β-D葡糖醛酸）琼脂来确认第一阶段试验，其结果与传统确认试验相当。优选的改进方法不再将气体的存在作为检测标准，而是使用显色琼脂培养基来确认大肠杆菌的存在，并在48小时内得出结果。通过公共卫生实验室服务处（PHLS）贝类外部质量保证计划，向其他实验室分发模拟样本和选定的大肠杆菌菌株，结果发现标准方法和改进方法得出的结果没有显著差异。
